ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
September 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
Mahmoud Lotfy, Alice Ying, Mohamed Abdou, Dong Won Lee, Mu-Young Ahn
Fusion Science and Technology | Volume 76 | Number 5 | July 2020 | Pages 605-615
Technical Paper | doi.org/10.1080/15361055.2020.1724737
Articles are hosted by Taylor and Francis Online.
Available experimental efforts on ceramic pebble beds and their associated constitutive equations are necessarily derived from single-effect tests where one parameter is varied and its effects are isolated and studied separately (e.g., using constant temperatures and externally applied loads). These experiments are incapable of reproducing the true multiple/synergistic effects of the physics that occur in real blankets, and the phenomena arising from the interactions of single effects are yet to be discovered. It is unclear whether the combined effect of plasticity and creep under reactor-relevant loading conditions will either enable the altered pebble bed packing configuration to reach an acceptable self-regulating temperature state or significantly deteriorate its heat transfer efficiency and subsequent tritium release. Therefore, studying the isolated thermal and mechanical effects is not sufficient to predict pebble bed behavior. It is the coupling and interdependence between the dynamic thermal and mechanical fields, as well as the synergistic effects between the various modes of deformation, that are key to fully understanding and predicting pebble bed behavior in a realistic fusion environment. However, previous mock-up experimental campaigns thus far have suffered from critical shortfalls that have severely hamstrung their scientific impact. The lack of experimental data that incorporate multiple-effects interactions in addition to the complexity of building a full-scale breeder unit mock-up triggered the need for this experimental effort. The body of work presented in this paper serves to (1) establish and validate the practicality of various volumetric heating simulation techniques for representative thermomechanical study, (2) recreate a prototypical breeder unit’s thermal-hydraulic behavior using a scaled-down reduced-activation ferritic steel box with optimized manifold design, (3) evaluate the thermomechanical properties of the pebble bed using a novel nonintrusive in situ tactile-pressure-sensing technology capable of generating real-time contact pressure maps that reveal spatial and temporal stress evolution, and (4) develop and benchmark a thermomechanical finite element method code that is able to predict the pebble bed’s thermomechanical evolution under the effects of creep and thermal cycling. The results of this study not only present novel experimental techniques and data that enhance our understanding of synergistic thermomechanical interactions and effects, but they also provide valuable data to serve as a basis for validation of the most recent pebble bed numerical models. Finally, it is worth mentioning that this work is part of a compendium around the Thermomechanical Solid Breeder Multiple Effects Experiment experimental campaign, known as TESOMEX. While this paper primarily focuses on novel heating and instrumentation techniques along with their opportunities and limitations, the other two papers shed more light on the prototypical thermomechanical evolution, pebble sintering, and possible modes of failure.